Stair system

ABSTRACT

A stair system including an upper tread having a substantially planar body portion, a stair nose portion located at one side of the planar body portion, and a dado located behind the stair nose portion, at least one lower tread, the lower tread having a substantially planar body portion, a stair nose portion located at one side of the planar body portion, a dado located behind the stair nose portion, and a groove located at a side opposite the stair nose portion, and at least two risers, each riser having a substantially planar body portion. In the stair system, one of the at least two risers is receivable between the dado of the upper tread and the groove of the lower tread and the other of the at least two risers is receivable in the dado of the lower tread. Methods for assembling a stair system are also provided.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention is generally directed to a stair system, and moreparticularly to modular treads and risers of a stair system.

2. Description of Related Art

Generally, stair systems having nose moldings have been constructed in asimilar manner using the same basic methods. For example, most stairsystems employ a plurality of stringers having tread sides cut out, onwhich are secured tread sub flooring that span between the stringers.The stringers also have riser sides cut out, on which are secured risersub floorings that also span between the stringers. Depending on thefinishing materials for the stair system, a tread and riser may bemounted to the tread sub flooring or carpeting with or without paddingmay be affixed to the tread sub flooring and riser sub flooring. Wherecarpeting is used, the tread sub flooring may provide an overhang toallow the carpet to be affixed to the underside of the overhang, therebyhiding the means of fastening the carpet to the tread sub flooring. Subflooring is normally secured using nails, screws, and/or adhesives

Because most stair systems are normally built from the top down, in thecase of steps having a wood finish, the top most tread is attached usingadhesive and a stair nose is attached to the end of the tread to overlapa portion of the tread and to cover the remainder of the tread subflooring. Generally the stair nose extends beyond the tread sub flooringa sufficient distance to allow a riser to be disposed beneath the stairnose.

The first step below the top step is assembled by placing a riserunderneath the stair nose and affixing it to the riser sub flooringusing either fasteners or adhesive. The next tread must be cut to have asquare edge, as it must abut the riser. Then the stair nose is attachedto the end of the tread to overlap a portion of the tread and to coverthe remainder of the tread sub flooring as discussed above. This processis repeated for each successive step.

In an alternative stair system, the stair nose may be affixed to thetread by using a tongue and groove relationship. The tread and risersare affixed to the tread sub flooring and riser sub flooring usingfasteners or adhesive as described above.

In all of the above cases, it is important that expansion of the wood beaccounted for in the assembly of the stairs. As such, sufficient gapsmust be provided between pieces of wood to allow the individual piecesto expand.

The first system permits the tread and risers to be free-floating, allowthem to contract and expand with changes in temperature and humidity.However, they are unattractive in that the stair nose is higher than thetread because of the overlapping arrangement.

The second system does allow the tread and stair nose to be coplanar,but because they are joined by the tongue and groove, the system doesnot allow the tread and risers to be free-floating.

U.S. Pat. No. 6,115,975 proposes a solution to providing a nose stairthat is coplanar with the tread, but still allows the tread and riser tobe free floating. The stair system provides a stair nose connected by atongue and groove arrangement to a tread. A back molding is affixed tothe tread and includes a groove to receive a riser therein. Acorresponding groove is formed in the stair nose such that the riser isheld between the stair nose and the back molding. In this manner, theriser can be allowed to expand and contract with the temperature andhumidity, thereby providing treads and risers that are free floating.

While the solution proposed in U.S. Pat. No. 6,115,975 address theproblems identified above, it is a complicated system that requires manyadditional components. As a result the assembly process is unnecessarilycomplicated.

BRIEF SUMMARY OF THE INVENTION

According to principles of this invention, a stair system is providedthat minimizes the components of the stair system and provides anefficient assembly process. The stair system includes an upper treadhaving a substantially planar body portion, a stair nose portion locatedat one side of the planar body portion, and a dado located behind thestair nose portion, at least one lower tread, the lower tread having asubstantially planar body portion, a stair nose portion located at oneside of the planar body portion, a dado located behind the stair noseportion, and a groove located at a side opposite the stair nose portion,and at least two risers, each riser having a substantially planar bodyportion. In the stair system, one of the at least two risers isreceivable between the dado of the upper tread and the groove of thelower tread and the other of the at least two risers is receivable inthe dado of the lower tread.

In another aspect, the groove of the at least one lower tread may beformed in an upper surface of the planar body portion. The groove of theat least one lower tread may be a rabbet or a dado.

In a different aspect, the at least one lower tread includes a pluralityof lower treads. Each of the lower tread may have a substantially planarbody portion, a stair nose portion located at one side of the planarbody portion, a dado located behind the stair nose portion, and a groovelocated at a side opposite the stair nose portion. In addition, the atleast two risers may include a plurality of risers such that the numberof risers corresponds to the number of lower treads plus the upperriser.

In yet another aspect, the stair nose portions of the upper tread mayhave a thickness substantially equal to the thickness of the planar bodyportion of the upper tread and the stair nose portion of the at leastone lower tread may have a thickness substantially equal to thethickness of the planar body portion of the at least one lower tread.Alternatively, the stair nose portions of the upper tread may have athickness greater than the thickness of the planar body portion of theupper tread and the stair nose portion of the at least one lower treadmay have a thickness greater than the thickness of the planar bodyportion of the at least one lower tread.

In a further aspect, the stair system includes at least two stringers,each stringer having a plurality of tread sides and a plurality of risersides, a plurality of tread sub-floorings corresponding to the pluralityof tread sides, each of the plurality of tread sub-floorings spanningbetween the at least two stringers and affixed to corresponding treadsides, and a plurality of riser sub-floorings corresponding to theplurality of riser sides, each of the plurality of riser sub-flooringsspanning between the at least two stringers and affixed to correspondingriser sides.

In still another aspect, the upper tread may be affixed to one of theplurality of tread sub-floorings, the at least one lower tread may beaffixed to another of the plurality of tread sub-floorings, and each ofthe at least two risers may be affixed to different riser sub-floorings.

In yet another aspect, an end of each of the tread sub-flooring mayextend beyond the lower adjacent riser sub-flooring such that the risersub-flooring is recessed behind the end of the tread sub-flooring.

In a further aspect, the upper tread may be affixed to one of theplurality of tread sub-floorings and the at least one lower tread isaffixed to another of the plurality of tread sub-floorings.

In still a further aspect, each of the plurality of risers may beaffixed to the corresponding dado. Alternatively, each of the pluralityof risers may be affixed to the end of the upper adjacent treadsub-flooring.

In accordance with another aspect of the present invention, a method forassembling a stair system, the stair system having at least twostringers, each stringer having a plurality of tread sides and aplurality of riser sides, a plurality of tread sub-flooringscorresponding to the plurality of tread sides, each of the plurality oftread sub-floorings spanning between the at least two stringers andaffixed to corresponding tread sides, and a plurality of risersub-floorings corresponding to the plurality of riser sides, each of theplurality of riser sub-floorings spanning between the at least twostringers and affixed to corresponding riser sides. The method includesaffixing a first riser to the lowermost riser sub-flooring of theplurality of riser sub-floorings, affixing a lower tread to one of theplurality of tread sub-floorings adjacent the lowermost risersub-flooring, the lower tread having a substantially planar bodyportion, a stair nose portion located at one side of the planar bodyportion, a dado located behind the stair nose portion, and a groovelocated at a side opposite the stair nose portion, the first riser beingreceivable in the dado of the lower tread, affixing a second riser tothe uppermost riser sub-flooring of the plurality of risersub-floorings, the second riser being received in the groove of thelower tread, and affixing an upper tread to one of the plurality oftread sub-floorings adjacent the uppermost riser sub-flooring, the uppertread having a substantially planar body portion, a stair nose portionlocated at one side of the planar body portion, and a dado locatedbehind the stair nose portion, the second riser being received betweenthe groove of the lower tread and the dado of the upper tread.

In another aspect, the method may include affixing an intermediate riserto one of the riser sub-floorings located between the lowermost risersub-flooring and the uppermost riser sub-flooring, and affixing anintermediate tread to one of the tread sub-floorings located between thelowermost tread sub-flooring and the uppermost tread sub-flooring, theintermediate tread having a substantially planar body portion, a stairnose portion located at one side of the planar body portion, a dadolocated behind the stair nose portion, and a groove located at a sideopposite the stair nose portion.

In a further aspect, where there is only three risers, the intermediateriser is received in the groove of the lower tread and the dado of theintermediate tread and the second riser is received in the groove of theintermediate tread and the dado of the upper tread.

In still another aspect of present invention, another method forassembling a stair system is provided, where the stair system has atleast two stringers, each stringer having a plurality of tread sides anda plurality of riser sides, a plurality of tread sub-flooringscorresponding to the plurality of tread sides, an end of each of thetread sub-flooring extends beyond the lower adjacent riser sub-flooringsuch that the riser sub-flooring is recessed behind the end of the treadsub-flooring, each of the plurality of tread sub-floorings spanningbetween the at least two stringers and affixed to corresponding treadsides, and a plurality of riser sub-floorings corresponding to theplurality of riser sides, each of the plurality of riser sub-flooringsspanning between the at least two stringers and affixed to correspondingriser sides. The method includes affixing a first riser to the lowermosttread sub-flooring of the plurality of tread sub-floorings, affixing alower tread to the lowermost tread sub-flooring of the plurality oftread sub-floorings adjacent the lowermost riser sub-flooring, the lowertread having a substantially planar body portion, a stair nose portionlocated at one side of the planar body portion, a dado located behindthe stair nose portion, and a groove located at a side opposite thestair nose portion, the first riser being received in the dado of thelower tread, affixing a second riser to the uppermost tread sub-flooringof the plurality of tread sub-floorings, and affixing an upper tread tothe uppermost tread sub-flooring of the plurality of tread sub-flooringsadjacent the uppermost riser sub-flooring, the upper tread having asubstantially planar body portion, a stair nose portion located at oneside of the planar body portion, and a dado located behind the stairnose portion, the second riser being received in the dado of the uppertread.

In another aspect, the method includes affixing an intermediate riser toone of the tread sub-floorings located between the lowermost treadsub-flooring and the uppermost riser sub-flooring, and affixing anintermediate tread to one of the tread sub-floorings located between thelowermost tread sub-flooring and the uppermost tread sub-flooring, theintermediate tread having a substantially planar body portion, a stairnose portion located at one side of the planar body portion, a dadolocated behind the stair nose portion, and a groove located at a sideopposite the stair nose portion.

In a further aspect, where there is only three risers, the intermediateriser is received in the groove of the lower tread and the dado of theintermediate tread and the second riser is received in the groove of theintermediate tread and the dado of the upper tread.

Further scope of applicability of the present application will becomemore apparent from the detailed description given hereinafter. However,it should be understood that the detailed description and specificexamples, while indicating preferred embodiments of the invention, aregiven by way of illustration only, since various changes andmodifications within the spirit and scope of the invention will becomeapparent to those skilled in the art from the detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will become more fully understood from thedetailed description given hereinbelow and the accompanying drawingswhich are given by way of illustration only, and thus are not limitativeof the present invention and wherein:

FIG. 1 is a partially exploded perspective view of the stair systemaccording to a first exemplary embodiment; and

FIG. 2 is a partially exploded perspective view of the stair systemaccording to a second exemplary embodiment.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIG. 1, the stair system 100 according to the firstexemplary embodiment includes conventional stringers 110 (one shown),each stringer 110 provides a plurality of tread sides 112 and aplurality of riser sides 114 formed therein. A tread sub flooring 116spans between corresponding tread sides 112 and a riser sub flooring 118spans between corresponding riser side 114. The stringers 110, tread subfloorings 116, and riser sub floorings 118 are assembled usingconventional techniques including fasteners and/or adhesives.

The stair system 100 includes at least two different treads depending onthe location of the tread. As seen in FIG. 1, the uppermost tread or toptread 120 has a planar body portion 122 and a stair nose portion 124. Adado 126 is provided behind the stair nose portion 124 and extends alongthe length of the planar body portion 122. As shown in FIG. 1, the stairnose portion 124 may have a thickness equal to the planar body portion122, although it is understood that the stair nose portion 124 may havea greater thickness than the planar body portion 122.

The stair system 100 includes one or more lower treads 130. Each lowertread 130 has a planar body portion 132 and a stair nose portion 134. Adado 136 is provided behind the stair nose portion 134 and extends alongthe length of the planar body portion 132. A rabbet 138 is provided atthe edge opposite the stair nose portion 134 and extends along thelength of the planar body portion 132. Preferably, the width of therabbet 138 corresponds to the width of either dado 126, 136 depending onthe type of tread, either the upper or lower tread 120, 130, arrangedabove it. As shown in FIG. 1, the stair nose portion 134 may have agreater thickness than the planar body portion 132, although it isunderstood that the stair nose portion 134 may have the same thicknessas the planar body portion 132. Preferably, the stair nose portion 134of the lower tread 130 has the same thickness of the stair nose portion124 of the upper tread 120.

In addition to the two types of treads discussed above, the stair system100 includes at least two risers 140. Each riser 140 has a substantiallyplanar body 142 and is configured to cooperate with one or more of thetreads to form the stair system 100.

The treads 120, 130 and risers 140 can be made out of natural plankwood, such as oak plank. However, the treads 120, 130, and risers 140can be made out of composites or other preformed materials. In addition,the treads 120, 130, and risers 140 can be provided in many conventionalplank widths and thickness, such as, three-quarter inch or one inchthick, as well as custom sizes. Preferably, the treads 120, 130 aresized such that the planar body portion is sufficiently sized to coverthe tread sub flooring and that the rabbets and dados correspond to thethickness of the risers. In addition, it is desirable that the depth ofthe dados and rabbets are selected such that the risers are free toexpand within the corresponding dado and/or rabbet without applying alarge expansion force to the corresponding treads.

Next, an exemplary method of assembling the stair system 100 will bedescribed. After the stringers 110, tread sub floorings 116, and risersub floorings 118 are assembled using conventional techniques includingfasteners and/or adhesives, the rest of the stair system is attached.Generally, this process begins at the bottom of the stair system 100 andprogresses up the stair system, although it is understood that atop-down approach may also be used.

First, one of the plurality of risers 140 is affixed to the surface ofthe riser sub flooring 118 using adhesive. Because this riser 140 islocated at the bottom of the stair system 100, it is preferably to onlyuse an adhesive. However, it is understood that fasteners can be usedand that if the fasteners are counter-sunk, then the holes may be filledin to hide their location. Alternatively, depending on the flooring thatthe stair system 100 rests on, that the flooring and/or the stair noseportion 134 may hide fasteners.

As seen in FIG. 1, the riser 140 extends above the corresponding treadsub flooring 116 such that the lower tread 130 can be fitted over theriser 140 and that the dado 136 receives the riser 140 therein. Thelower tread 130 can be affixed to the tread sub flooring 116 usingfasteners and/or adhesives. Preferably, the planar body portion 132 isaffixed with adhesive while the fasters (not shown) extend through therabbet 138 into the tread sub flooring 116. In this manner, the lowertread 130 can reliably be mounted to the tread sub flooring 116, whileallowing the fasteners to be hidden from view by the riser 140 insertedat the back of the lower tread 130.

Specifically, the next riser 140 is attached to riser sub flooring 118adjacent the rabbet 138. The riser 140 can be attached to the rabbet 138 and/or the riser sub flooring 118 using adhesive. As noted previously,the riser 140 may also be attached using fasteners that are counter sunkand filled in and/or the fasteners may be hidden behind the stair noseportion 134. This process is repeated with the remaining lower treads130 until the top of the stair system 100 is reached.

As seen in FIG. 1, the upper most riser 140 extends above thecorresponding tread sub flooring 116 such that the upper tread 120 canbe fitted over the riser 140 and that the dado 126 receives the riser140 therein. The upper tread 120 can be affixed to the tread subflooring 116 using fasteners and/or adhesives. Because no rabbet isprovided in the upper tread 120, a continuous planar finish is achieved.

Depending on the materials selected, the above-described stair system100 can be provided as a free standing stair system (i.e., no wallsprovided at either side of the stair system), supported by one wall, orsupported by wall on both sides of the stair system. Specifically,depending on the finishing of the wood, the stair system can have anaesthetic appearance without further finishing.

Because there are times when it is desirable to remove and replaceexisting tread and/or carpeting, the stair system 100 can be readilyadapted to such a process. For example, as seen in FIG. 2, a stairsystem 200 similar to stair system 100 can be provided. In thisarrangement, existing stringers 210 (one shown) may be used. Eachstringer 210 includes a plurality of tread sides 212 and a plurality ofriser sides 214 formed therein. Existing tread sub flooring 216 spansbetween corresponding tread sides 212 and existing riser sub flooring218 spans between corresponding riser side 214. In this exemplaryembodiment, the tread sub flooring 216 extends beyond the riser subflooring a predetermined distance to allow carpeting to wrap around theedge of the tread sub flooring 216 and to be affixed to a lower surfaceof the tread sub flooring 216. The stringers 210, tread sub floorings216, and riser sub floorings 218 were previously assembled usingconventional techniques including fasteners and/or adhesives.

As described above for stair system 100, the stair system 200 includesat least two different treads depending on the location of the tread. Asseen in FIG. 2, the uppermost tread or top tread 220 has a planar bodyportion 222 and a stair nose portion 224. A dado 226 is provided behindthe stair nose portion 224 and extends along the length of the planarbody portion 222. As shown in FIG. 2, the stair nose portion 224 mayhave a greater thickness than the planar body portion 222, although itis understood that the stair nose portion 224 may have the samethickness as the planar body portion 222.

The stair system 200 includes one or more lower treads 230. Each lowertread 230 has a planar body portion 232 and a stair nose portion 234. Adado 236 is provided behind the stair nose portion 234 and extends alongthe length of the planar body portion 232. A second dado 238 is providednear the edge opposite the stair nose portion 234 and extends along thelength of the planar body portion 232. Preferably, the width of thesecond dado 238 corresponds to the width of either dado 226, 236depending on the type of tread, either the upper or lower tread 220,230, arranged above it. As shown in FIG. 2, the stair nose portion 234may have a greater thickness than the planar body portion 232, althoughit is understood that the stair nose portion 234 may have the samethickness as the planar body portion 232. Preferably, the stair noseportion 234 of the lower tread 230 has the same thickness of the stairnose portion 224 of the upper tread 220.

In addition to the two types of treads discussed above, the stair system200 includes at least two risers 240. Each riser 240 has a substantiallyplanar body 242 and is configured to cooperate with one or more of thetreads to form the stair system 200.

The treads 220, 230 and risers 240 can be made out of natural plankwood, such as oak plank. However, the treads 220, 230, and risers 240can be made out of composites or other preformed materials. In addition,the treads 220, 230, and risers 240 can be provided in many conventionalplank widths as well as custom sizes. Preferably, the treads 220, 230are sized such that the planar body portion is sufficiently sized tocover the tread sub flooring and that the dados correspond to thethickness of the risers. In addition, it is desirable that the depth ofeach dado is selected such that the risers are free to expand within thecorresponding dado without applying a large expansion force to thecorresponding treads.

Finally, as seen in FIG. 2, a gap 250 is formed by the arrangement ofthe riser 240, tread sub flooring 216 and riser sub-flooring 218. Ifdesired, a pad or other sound dampening material may be placed in thegap to absorb sound during use of the stair system 200.

Next, an exemplary method of assembling the stair system 200 will bedescribed. After removing any old tread and/or carpeting from the treadsub floorings 216 and riser sub floorings 218, the rest of the stairsystem is attached. Generally, this process begins at the bottom of thestair system 200 and progresses up the stair system, although it isunderstood that a top-down approach may also be used.

First, because the riser sub flooring 218 is recessed from the end ofthe tread sub flooring 216, one of the plurality of risers 240 isaffixed to the end of the tread sub flooring 216 using adhesive and/orfasteners. Because this riser 240 is located at the bottom of the stairsystem 200, it is preferably to only use an adhesive. However, it isunderstood that fasteners can be used and that fasteners can be hiddenby the stair nose portion 234 of the adjacent lower tread 230.Alternatively, depending on the flooring that the stair system 200 restson, that flooring may also hide the fasteners.

As seen in FIG. 2, the riser 240 extends above the corresponding treadsub flooring 216 such that the lower tread 230 can be fitted over theriser 240 and that the dado 236 receives the riser 240 therein. Thelower tread 230 can be affixed to the tread sub flooring 216 usingfasteners and/or adhesives. Preferably, the planar body portion 232 isaffixed with adhesive while the fasters (not shown) extend through thesecond dado 238 into the tread sub flooring 216. In this manner, thelower tread 230 can reliably be mounted to the tread sub flooring 216,while allowing the fasteners to be hidden from view by the riser 240inserted at the back of the lower tread 230.

Specifically, the next riser 240 is attached to the tread sub flooring216 located above the second dado 238. The riser 240 can be attached tothe second dado 238 and/or the tread sub flooring 218 using adhesive. Asnoted previously, the riser 240 may also be attached using fasteners.This process is repeated with the remaining lower treads 230 until thetop of the stair system 200 is reached.

As seen in FIG. 2, the upper most riser 240 extends above thecorresponding tread sub flooring 216 such that the upper tread 220 canbe fitted over the riser 240 and that the dado 226 receives the riser240 therein. The upper tread 220 can be affixed to the tread subflooring 216 using fasteners and/or adhesives. Because there is nosecond dado provided in the upper tread 220, a planar finish isachieved.

As mentioned previously, the spaces 250 between the risers 240 and theriser sub flooring 218 may be filled with pads or other sound absorbingmaterial. Depending on the accessibility of the spaces, the pads may beinserted before securing the corresponding riser 240 to the tread subflooring 218 or after the riser 240 is secured to the tread sub flooring(e.g., one edge of the stair system 200 is temporarily exposed.)

Because the second exemplary stair system 200 will most likely be usedto replace existing stairs with old tread and/or carpeting, the stairsystem 200 will probably be supported by walls on both sides of thestair system to hide the space 250 between the riser 240 and the risersub flooring 218.

The previously described stair systems allow for quick and easilyassembly by minimizing the number of components provided for the stairsystem. In addition, the treads and risers may be prefabricated suchthat stair systems can be modular designs. Furthermore, the above stairsystems allow old tread and/or carpets to be replaced without removingthe entire stair system.

The invention thus being described, it will be obvious that the same maybe varied in many ways. Such variations are not to be regarded as adeparture from the spirit and scope of the invention, and all suchmodifications as would be obvious to one skilled in the art are intendedto be included within the scope of the following claims.

1. A stair system comprising: an upper tread having a substantiallyplanar body portion, a stair nose portion located at one side of theplanar body portion, and a dado located behind the stair nose portion;at least one lower tread, the lower tread having a substantially planarbody portion, a stair nose portion located at one side of the planarbody portion, a dado located behind the stair nose portion, and a groovelocated at a side opposite the stair nose portion; and at least tworisers, each riser having a substantially planar body portion, one ofthe at least two risers being receivable between the dado of the uppertread and the groove of the lower tread, the other of the at least tworisers being receivable in the dado of the lower tread.
 2. The stairsystem according to claim 1, wherein the groove of the at least onelower tread is formed in an upper surface of the planar body portion. 3.The stair system according to claim 2, wherein the groove of the atleast one lower tread is a rabbet.
 4. The stair system according toclaim 2, wherein the groove of the at least one lower tread is a dado.5. The stair system according to claim 1, wherein the at least one lowertread includes a plurality of lower treads, each of the lower treadhaving a substantially planar body portion, a stair nose portion locatedat one side of the planar body portion, a dado located behind the stairnose portion, and a groove located at a side opposite the stair noseportion; and wherein the at least two risers includes a plurality ofrisers such that the number of risers corresponds to the number of lowertreads plus the upper riser.
 6. The stair system according to claim 1,wherein the stair nose portions of the upper tread has a thicknesssubstantially equal to the thickness of the planar body portion of theupper tread and the stair nose portion of the at least one lower treadhas a thickness substantially equal to the thickness of the planar bodyportion of the at least one lower tread.
 7. The stair system accordingto claim 1, wherein the stair nose portions of the upper tread has athickness greater tan the thickness of the planar body portion of theupper tread and the stair nose portion of the at least one lower treadhas a thickness greater than the thickness of the planar body portion ofthe at least one lower tread.
 8. The stair system according to claim 1,further comprising: at least two stringers, each stringer having aplurality of tread sides and a plurality of riser sides; a plurality oftread sub-floorings corresponding to the plurality of tread sides, eachof the plurality of tread sub-floorings spanning between the at leasttwo stringers and affixed to corresponding tread sides; a plurality ofriser sub-floorings corresponding to the plurality of riser sides, eachof the plurality of riser sub-floorings spanning between the at leasttwo stringers and affixed to corresponding riser sides.
 9. The stairsystem according to claim 8, wherein the upper tread is affixed to oneof the plurality of tread sub-floorings, the at least one lower tread isaffixed to another of the plurality of tread sub-floorings, and each ofthe at least two risers are affixed to different riser sub-floorings.10. The stair system according to claim 8, wherein an end of each of thetread sub-flooring extends beyond the lower adjacent riser sub-flooringsuch that the riser sub-flooring is recessed behind the end of the treadsub-flooring.
 11. The stair system according to claim 10, wherein theupper tread is affixed to one of the plurality of tread sub-flooringsand the at least one lower tread is affixed to another of the pluralityof tread sub-floorings.
 12. The stair system according to claim 11,wherein each of the plurality of risers are affixed to the correspondingdado.
 13. The stair system according to claim 12, wherein each of theplurality of risers are affixed to the end of the upper adjacent treadsub-flooring.
 14. A method for assembling a stair system, the stairsystem having at least two stringers, each stringer having a pluralityof tread sides and a plurality of riser sides, a plurality of treadsub-floorings corresponding to the plurality of tread sides, each of theplurality of tread sub-floorings spanning between the at least twostringers and affixed to corresponding tread sides, and a plurality ofriser sub-floorings corresponding to the plurality of riser sides, eachof the plurality of riser sub-floorings spanning between the at leasttwo stringers and affixed to corresponding riser sides, the methodcomprising: affixing a first riser to the lowermost riser sub-flooringof the plurality of riser sub-floorings; affixing a lower tread to oneof the plurality of tread sub-floorings adjacent the lowermost risersub-flooring, the lower tread having a substantially planar bodyportion, a stair nose portion located at one side of the planar bodyportion, a dado located behind the stair nose portion, and a groovelocated at a side opposite the stair nose portion, the first riser beingreceived in the dado of the lower tread; affixing a second riser to theuppermost riser sub-flooring of the plurality of riser sub-floorings,the second riser being received in the groove of the lower tread; andaffixing an upper tread to one of the plurality of tread sub-flooringsadjacent the uppermost riser sub-flooring, the upper tread having asubstantially planar body portion, a stair nose portion located at oneside of the planar body portion, and a dado located behind the stairnose portion, the second riser being received between the groove of thelower tread and the dado of the upper tread.
 15. The method according toclaim 14, further comprising: affixing an intermediate riser to one ofthe riser sub-floorings located between the lowermost riser sub-flooringand the uppermost riser sub-flooring; and affixing an intermediate treadto one of the tread sub-floorings located between the lowermost treadsub-flooring and the uppermost tread sub-flooring, the intermediatetread having a substantially planar body portion, a stair nose portionlocated at one side of the planar body portion, a dado located behindthe stair nose portion, and a groove located at a side opposite thestair nose portion.
 16. The method according to claim 15, wherein thereis only three risers, the intermediate riser is received in the grooveof the lower tread and the dado of the intermediate tread and the secondriser is received in the groove of the intermediate tread and the dadoof the upper tread.
 17. A method for assembling a stair system, thestair system having at least two stringers, each stringer having aplurality of tread sides and a plurality of riser sides, a plurality oftread sub-floorings corresponding to the plurality of tread sides, anend of each of the tread sub-flooring extends beyond the lower adjacentriser sub-flooring such that the riser sub-flooring is recessed behindthe end of the tread sub-flooring, each of the plurality of treadsub-floorings spanning between the at least two stringers and affixed tocorresponding tread sides, and a plurality of riser sub-flooringscorresponding to the plurality of riser sides, each of the plurality ofriser sub-floorings spanning between the at least two stringers andaffixed to corresponding riser sides, the method comprising: affixing afirst riser to the lowermost tread sub-flooring of the plurality oftread sub-floorings; affixing a lower tread to the lowermost treadsub-flooring of the plurality of tread sub-floorings adjacent thelowermost riser sub-flooring, the lower tread having a substantiallyplanar body portion, a stair nose portion located at one side of theplanar body portion, a dado located behind the stair nose portion, and agroove located at a side opposite the stair nose portion, the firstriser being received in the dado of the lower tread; affixing a secondriser to the uppermost tread sub-flooring of the plurality of treadsub-floorings; and affixing an upper tread to the uppermost treadsub-flooring of the plurality of tread sub-floorings adjacent theuppermost riser sub-flooring, the upper tread having a substantiallyplanar body portion, a stair nose portion located at one side of theplanar body portion, and a dado located behind the stair nose portion,the second riser being received in the dado of the upper tread.
 18. Themethod according to claim 17, further comprising: affixing anintermediate riser to one of the tread sub-floorings located between thelowermost tread sub-flooring and the uppermost riser sub-flooring; andaffixing an intermediate tread to one of the tread sub-floorings locatedbetween the lowermost tread sub-flooring and the uppermost treadsub-flooring, the intermediate tread having a substantially planar bodyportion, a stair nose portion located at one side of the planar bodyportion, a dado located behind the stair nose portion, and a groovelocated at a side opposite the stair nose portion.
 19. The methodaccording to claim 18, wherein there is only three risers, theintermediate riser is received in the groove of the lower tread and thedado of the intermediate tread and the second riser is received in thegroove of the intermediate tread and the dado of the upper tread.